In the production of hydrocarbons from a subterranean formation penetrated by a wellbore, it is often necessary to address the problem of the production of fine particulate materials with the desired well fluids. Such fine particulate materials can cause abrasive wear on well components such as pumps, valves and tubular goods resulting in costly replacement. Additionally, these particulates must be separated from the desired well fluids before transport, processing or sale. Further, these particulate materials can accumulate in the wellbore and in the near wellbore area and greatly reduce or completely stop further production of the fluids of value.
Minimizing the production of particulate materials such as formation sand without reducing well productivity has long been the goal of sand control operations. Various technologies have been used including resin consolidation, gravel packing, overbalanced perforating with resin consolidation and the like. Each of these technologies has its own set of problems and limitations. These include problems in assuring placement uniformity and efficiency. Often, these technologies also have the undesired side effect of reducing well productivity.
In the case of gravel packing, placement efficiency is especially crucial. If even a single perforation is not tightly packed with gravel, formation sand will likely be produced in large quantities through the unpacked perforation(s). As a result, expensive separation equipment is required, the erosion of downhole and surface equipment occurs and eventually the well itself is jeopardized through build up of sand in the wellbore. Gravel packs routinely include the use of a gravel-pack screen in the wellbore, with the annulus between the screen and the wellbore itself being tightly packed with gravel. By its very nature, this process requires packing the perforation tunnels with gravel and reducing potential well productivity.
Recently, technology has been introduced that combines the principles of fracturing with those of gravel packing. This technology is generically referred to as frac-and-pack. By creating a small fracture followed by an annulus pack and gravel pack screen, improved well productivity can be obtained relative to that of conventional gravel packing. The need to ensure packing of every perforation still requires use of the expensive gravel pack screen and the production limiting annulus pack.